Robust Hot Electron and Multiple Topological Insulator States in PtBi2
Robust Hot Electron and Multiple Topological Insulator States in PtBi2
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PtBi2 中的鲁棒热电子和多重拓扑绝缘体态
DOI：
10.1021/acsnano.9b09564
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发表时间：
2020-02-01
期刊：
影响因子：
17.1
通讯作者：
Jia, Jinfeng
中科院分区：
文献类型：
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作者：
Nie, Xiao-Ang;Li, Shujing;Jia, Jinfeng
二维拓扑绝缘体只具有一个具有非平凡拓扑的体隙，它在费米能级上保护一维边界态。我们发现了一个超越这一范畴的物质的量子相：多重拓扑绝缘体。它有一个拓扑间隙的梯子；每个间隙保护一个健壮的边状态。我们证明了单层van der Waals材料PtBi2是一种二维多层拓扑绝缘体。借助于扫描隧道谱，我们直接显示了样品上纳米尺寸的一维热电子(和空穴)通道。此外，我们通过直接展示它们对晶体取向、边缘几何形状和样品温度变化的稳健性来确认这些通道的拓扑保护。所发现的拓扑型热电子材料有可能成为未来高效的光催化剂。
A two-dimensional topological insulator features (only) one bulk gap with nontrivial topology, which protects one-dimensional boundary states at the Fermi level. We find a quantum phase of matter beyond this category: a multiple topological insulator. It possesses a ladder of topological gaps; each gap protects a robust edge state. We prove a monolayer of van der Waals material PtBi2 as a two-dimensional multiple topological insulator. By means of scanning tunneling spectroscopy, we directly visualize the one-dimensional hot electron (and hole) channels with nanometer size on the samples. Furthermore, we confirm the topological protection of these channels by directly demonstrating their robustness to variations of crystal orientation, edge geometry, and sample temperature. The discovered topological hot electron materials may be applied as efficient photocatalysts in the future.